I am quite sure most of this is already explained in other big bridgeboard threads. At least XT IDE stuff.

Only A2286+ have IDE support in BIOS. But it must be configured in BIOS too. Floppy drive type must be also exactly right. This is ancient PC that didn't even attempt to be any kind of plug and play.. Each device base address must be conflict free, including Janus BIOS extensions address.